This video shows how to build a line graph from scratch but it is missing some valuable information, for instance the difference between independent and dependent variables and which axis they belong to.
This explains briefly what the median is and how to find it, and gives two separate examples, one is for when there is an even amount of numbers and the other is when there are an odd amount of numbers. The only problem is, his numbers are already placed in order and this is not always the case.
Theoretical vs. Experimental